"The One With The Kips" is the fifth episode of the fifth season of Friends, which aired on NBC on October 29, 1998.
After nearly getting caught together by Joey, Chandlerand Monica decide to go away for a romantic weekend together, and they each tell the rest of the friends that they have to go away for work. Monica gets upset when she finds lipstick on one of the glasses in the bathroom and, after insisting they change rooms, finds something wrong with several more rooms before she finds one that satisfies her. Meanwhile, Chandler is trying to watch a high-speed car chase on TV and seems more interested in that than he does in spending time with Monica. They have a fight and Monica storms out of the hotel room. Back at home Chandler thinks things are over between them, which makes Monica realize Chandler has never been in a relationship that survived the first fight before. She tells him that it's nothing to freak out about and welcomes him to an adult relationship.
Ross tries to tell Rachel that Emily has demanded that he can't see her anymore and that he is going along with it to make his marriage work, but he fails becauseLaPooh died and her nose starts bleeding. When he finally manages to tell her, she is furious and upset and worries that she will become the next "Kip," a reference to Chandler's former roommate who dated Monica and after a messy breakup got "phased out" of the group.
The hotel where Chandler and Monica stayed called and left a message saying there was an eyelash curler left in the room. Joey confronts Chandler about it, outrageously suspecting that Chandler has gone on a gay cruise. Toward the end of the episode, Joey hears Monica ask Rachel to borrow her eyelash curler because she lost hers. He puts two and two together and starts to freak out. To keep him from exclaiming it to everyone, Monica and Chandler drag him into the bedroom and confess that they've been sleeping together, but swear him to secrecy.
Phoebe is offended when Rachel claims that she always assumed that Phoebe would be the first one to be phased out of the group. However, Rachel convinces her to leave the group with her and start a new group. Phoebe agrees, but only if they can take Joey with them.